Steam-boiler.



No. 767,923. PATENTED AUG. 16, 1904. F. BURGER & H, M. WILLIAMS. STEAMBOILER.

APPLICATION FTLED DBO. 17, 1902. NO MODEL. 2 SHBETSSHEET 1.

N. i L

Flu-van l'oza No. 767,923. PATENTED AUG. 16, 1904 M. WILLIAMS. 4 STEAMBOILER.

APPLICATION FILED DEC. 17, 19oz.

F. BURGER & H

2 SHEETS-SHEET 2,

N0 MODEL.

UNITED STATES Patented August 16, 1904.

PATENT OFFICE.

FRANZ BURGER AND HENRY M. WILLIAMS, OF FORT WAYNE, INDIANA; SAID BURGERASSIGNOR OF ONE-HALF OF HIS RIGHT TO SAID WILLIAMS.

STEAM-BOILER- SPECIFICATION forming part of Letters Patent No. 767,923,dated August 16, 1904.

Application filed December 17, 1902. Serial No. 135,627. (No model.)

To aZZ whom, it may concern.-

I Be it known that we, FRANZ BURGER and HENRY M. WILLIAMS, both citizensof the United States, residing at Fort Wayne, in the county of Allen andState of Indiana, have invented certain new and useful Improvements inSteam-Boilers, of which the following is a specification.

This invention relates to steam-boilers, and particularly to means fordirecting and controlling the passage of the products of combustion overthe heating-surfaces of the boiler.

The invention will be fully described hereinafter, reference being hadto the accompanying drawings, in which Figure 1 is a sectional sideelevation of a boiler embodying our present invention, and Fig. 2 is avertical transverse section.

.The boiler consists of two outer semicylindrical shells A and B,connected together at their longitudinal edges at O in any suitablemanner, and two similar but smaller inner shells a and 6, connectedtogether at their longitudinal edges at c, and the space between theseinner and outer shells forms the steam and water spaces of the boilerand the space inclosed by the inner shells forms the fire-box or furnaceof the boiler. The lower portions of the inner and outer shells are cutawayto form a longitudinal slot in which are placed grate-bars forsupporting fuel, as indicated by 3. An opening is cut in the top of theouter shell to afiord communication with the usual steam-dome L. Theoutside shell is inclosed by a jacket I, a space being left betweenthem, and this casing has connected to it an upwardly-extending casingJ, which surrounds the steam-dome with a space between them, and theupper end of the casing J is contracted to'form a discharge-nozzle K,through which the products of combustion finally escape to theatmosphere. The casing I is provided with a longitudinal slot 2', whichis closed by a series of hinged flaps N. Preferably there will be aseries of flaps N hinged to each edge of the slot 2' and normallyinclining toward each other to meet at their free edges; but obviouslyflaps may be hinged to one edge only of the slot and lie flat across theslot. These flaps will extend nearly from end to end of casing or jacketI, except within the area of the casing J. There will thus always be alimited free opening around the dome L for the escape of the products ofcombustion. The slot 2' and flaps N are covered by casings O, whichcommunicate at one end with the casing J and are closed at their otherends, and these casings O form conduits through which products ofcombustion passing the flaps N are conveyed to the casing J.

Within the furnace and extending longitudinally on each side of thegratebars or grat ing are two guard-walls H, made of fire-resistingmaterial, and the coal or fragments of incombustible material will beconfined between these walls. A space will be left between each wall Hand the opposing side of the furnace, and from this space a series ofshort inclined tubes G lead through the water-space of the boiler to thespace between the outer shell of the boiler and the jacket I, andthrough these tubes all the products of combustion must pass to thespace between the jacket and boiler.

To supply the necessary air to the furnace, we preferably employ aforced draft, and for this purpose a series of pipes 20 are supportedbeneath the grating and provided with nozzles through which 'air may beforced by any approved means. This forced draft may also be supplementedby an induced draft, and for this purpose we may employ a pipe M,leading to the nozzle K, and air or steam may be forced through thispipe to create the induced draft. Preferably the pipe M will be providedwith a controlling-valve, as indicated by m.

Such being the preferred form of construction, the operation is asfollows: The products of combustion generated in the furnace will firstascend to the top of the furnace and then descend to the spaces betweenthe walls H and the sides of the furnace, from whence they will passthrough the tubes G into the space between the jacket I and the boiler.If only a light draft is being used, the flaps N will open only slightlyand the gases will escape slowly and will therefore be in contact withthe boiler for a considerable period, thus enabling the boiler-shells toabsorb more of their heat.

It is obvious that by controlling the draft the escape of the productsof combustion from the nozzle K can be controlled, for the extent towhich the flaps N will open will be automatically controlled by theforce of the draft.

Each flap N may have a lug a, adapted to engage the casing I to preventthe flaps from opening too far or from swinging over onto the casing, orany other means may be employed forthis purpose.

Without limiting ourselves to the precise construction illustrated anddescribed, we clairn 1. The combination with a longitudinal boiler andits furnace, of a jacket inclosing said boiler to leave a space betweenthem, said jacket having a longitudinal slot in its top, hinged flapsnormally closing said slot and conduits for conveying the products ofcombustion from the furnace to said space, substantially as set forth.

2. The combination with a longitudinal boiler and its furnace, of ajacket inclosing said boiler to leave a space between them, said jackethaving a longitudinal slot in its top, hinged flaps normally closingsaid slot, and tubes leading from the lower part of the furnace throughthe water-space of the boiler to the said space between the boiler andjacket, substantially as set forth.

3. The combination with a boiler and its furnace, of a jacket inclosingthe boiler to leave a space between them and having a longitudinal slotin its top, hinged flaps normally closing said slot, a casing inclosingsaid slot and flaps and having a restricted dischargeopening, andconduits for conveying the products of combustion from the furnace tothe space between the boiler and easing, substantially as set forth.

4. The combination with a boiler and its furnace, of a jacket inclosingsaid boiler to leave a space between them and having a longitudinal slotin its top, hinged flaps normally closing said slot, means to limit theopening movement of the flaps, and conduits for conveying the productsof combustion from the furnfitce to the said space, substantially as setfort 5. The combination with a boiler and its furnace, of a jacketinclosing the boiler to leave a space between them and having alongitudinally-extending slot in its top, hinged flaps normally closingsaid slot. a casing inclosing said slot and flaps and having arestricted discharge-opening, conduits for conveying the products ofcombustion from the furnace to the said space, and means for creating adraft through the furnace, said space and the said casing, substantiallyas set forth.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

FRANZ BURGER. HENRY M. VVILLI-AMS. Witnesses:

GEO. D. CRANE, O. ERvIN.

